Electrolytic cell and in anodes used in such cells



ELECTROLYTIC CELL AND IN ANODES USED IN SUCH CELLS Sept. 27, 1932. o.CONRADTY Filed Feb. 25, -1951 I H r ,2 p

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Patented Sept. 27, 1932 UNITED STATES OTTMAR CONRADTY, F NUREMIBERG,GERMANY ELECTROLYTIC CELL AND IN ANODES USED IN SUCH CELLS Applicationfiled February 25, 1931, Serial No. 518,234, and in Germany' July 23,1930.

My invention relates to improvements in electrolytic cells and in anodesused in such cells. In electrolytic processes now in use the diaphragmand the cathode are rapidly destroyed by acid action thereon, andparticularly such diaphragms are subject to injury which are made fromasbestos, asbestos paper and the like. Particularly those parts of thediaphragm and the cathode are subject to injury by acid action where thesurface of the cathode has no anode surface cipposite thereto, and wheretherefore there is no direct transmission of ions and no formation oflye. Experiments have shown that in vertical electrodes the diaphragm isinjured more rapidly than in cells having horizontal electrodes. Thealkali hydroxide formed on the cathode sinks by reason of its highspecific gravity, and therefore in the upper parts of the cell thecathode is protected by the hydroxide being formed at such parts onlywhich are opposed to an anode surface, while between the anodes, wherethere is not transmission of ions, there are zones which are poor in lyeand which therefore are subject to acid action. The diaphragm and thecathode are destroyed, and the cell must be thrown out of operation.

' The object of the improvements is to provide an electrolytic cell andan anode in which this objection is obviated, and with this object inview my invention consists in constructing the adjacent sections of theanode so that the whole surface of the cathode, or at least the topparts'thereof are opposed by anode surfaces, so that there is atransmission of ions from ,the anode to all the parts of the cathode.With this object in view,my invention consists in constructing theanodes 40 so that the adjacent surfaces of' adjacent anodes cover eachother, at least at their top parts, transversely of the cathode.

In a preferred embodiment of the invention the sections of the anode arerhomboid or trapezoidal in cross-section and arranged relatively t0,eachother so that the adjacent sides of thesections are substantiallyparallel to each other and at acute angles to the surface of thecathode.

For the purpose of explaining the invention several examples embodyingthe same have been shown in the accompanying drawing in which the samereference characters have been used in all the views to indicatecorresponding parts. In said drawing,

Fig. 1 is'a diagrammatical sectional elevation showing the electrolyticcell,

Fig. 2 is a diagrammatical sectional elevation taken on the line 22 ofFig. 1,

Fig. 3 is a diagrammaticalsectional plan View taken on the'line 3--3 ofFig. 1 and showing the construction of the anode now in use,

Figs. 4 and 5 are similar sectional plan views showing myimprovedanodes,

Fig. 6 is a detail plan view on an enlarged' scale showin a portion. ofthe electrode illustrated in ig. 3, and

Fig. 7 is a similar plan view showing a portion of the electrodes shownin Figs. 1 7 and 5. I

In Fig. 1, I'have illustrated an electrolytic cell having verticalelectrodes, the said cell comprising an anode a made for example fromgraphite, a diaphragm b and a cathode 0. As is shown in Fig.3 the anodea comprises several sections which are spaced from each other. In thecell certain parts of the diaphragm are subject to injury by acidaction, and the said parts have been illustrated in Fig. 1 by the letterd. The alkali hydroxide which is formed-at the top parts (i sinks to thebottom, and therefore only such parts of the surface of the diaphragmand the cathode are protected where hydroxide is being formed, while thelower portions of the diaphragm and the cathode are protected by thehydroxide spreading on the surface thereof. In the'construction shown inFig. 3 the spaced sectional electrodes (1 are rectanis subject at suchparts to injury by acid action. In Fig. 2 the said portions of thediaphragm have been indicated by the letters In Fig. 4 I have shown thenew construction of the anode a As is shown in the said figure thesectional anodes cover each other at their spaces, the sectional anodesa being rhomboid in cross-section and the spaces between the same beingdisposed angularly of the diaphragm. By thus constructing the sectionalanodes the total surface thereof is enlarged, and on the whole surfaceof the cathode'migration of ions and formation of the hydroxide takerplace, so that also the upper part of the cell is not injured by acidaction on the diaphragm and the cathode caused by the hydroxide sinkingto the bottom. Thus the operation is made more reliable. Further theactive surface, of the anode is reduced in aless degree by wear becausethe spaces between the anodes are increased by'we'ar in a less degree asis shown in Figs. 6 and 7 In Fig. 6 the original distance between theelectrodes is e and after wear the said space is increased to 6". In'asimilar way the distance is increased in Fig. 7 from c to e. But thesectional electrodes still cover each other in transverse direction,even if the wear proceeds very far, so that the active surface of theanode is not changed.

Thereby also thedensity of the current remains constant for acomparatively long time, which is of high practical importance,

because the more uniform the density of the current is the longer is thelife of the graphite anode. Further by providing a uniform and largeanode surface the tension of the bath may be reduced, -while isdesirable in view of the reduced consumption of current.

In Fig. 5 I have shown a modification in which the sections a of theanodes are trapezoidal in cross-section.

I claim:

1. An electrolytic cell, comprising spaced anodes, a diaphragm, and acathode in position for cooperating with said anodes, the anodescovering one another transversely of the cathode, and presenting theretoa subtion for cooperatlng with said anodes, the.

adjacent spaced surfaces of the anodes being disposed at acute anglesrelatively to the cathode and so as to cover one another transversely ofthe cathode, and presenting thereto a substantially unbroken surface,spaced substantially uniformly from the cathode.

3. An electrolytic cell, comprising spaced anodes rhomboid in section, adiaphragm, and a cathode in position for cooperating with said anodes,the anodes covering each other transversely of the cathode, andpresenting thereto a substantially unbroken surface, spacedsubstantially uniformly from the cathode.

4. An electrolytic cell, comprising spaced anodes trapezoidal insection, a diaphragm, and a cathode in position for cooperating withsaid anodes, the anodes covering each other transversely of the cathode,and presenting thereto a substantially unbroken surface, spacedsubstantially uniformly from the cathode.

5. An electrolytic cell, comprising spaced vertical anodes, a diaphragm,and a cathode in position for cooperating with said anodes, the anodescovering one another at their top parts transversely of the cathode, andpre-.v senting thereto a substantially unbroken surface, spacedsubstantially uniformly from the cathode. Y

6. An electrolytic cell, comprising spaced vertical anodes, a.diaphragm, and a cathode in position for cooperating with said anodes,the adjacent spaced surfaces of the anodes being disposed at their topparts at acute angles relatively to the cathode and so as to cover oneanother transversely of the cathode,

and presenting thereto a substantially unbroken surface, spacedsubstantially uniforml from the cathode.

7. n electrolytic cell, comprising spaced 'vertical anodes rhomboid insection, a diaphragm, and a cathode in position for cooper ating withsaid anode, the anodes covering each other transversely of the cathode,and

;presenting thereto a substantially unbroken surface, spacedsubstantially uniformly from the cathode.

8. An electrolytic cell, comprising spaced vertical anodes trapezoidalin section, a diaphragm, and a cathode in position for cooperating withsaid anode, the anodes covering each other transversely of the cathode,and presenting thereto a substantially unbroken surface, spacedsubstantially uniformly from the cathode.,

9. An anode for electrolytic cells for the composition of aqueousalkaline solutions composed of sections which are trapezoidal incross-section.

10. An anode for electrolytic cells for the decomposition of aqueousalkaline solutions, composed of sections which are rhomboidal insection.

11. An electrolytic cell comprising spaced anodes, a diaphragm and acathode in position for cooperating with said anodes, current beingdelivered, during the operation of the cell, to all parts of thecathode, the anodes covering each other transversely of the cathode, andpresenting thereto a substantiall unbroken surface, spaced substantiallyun formly from the cathode.

12. An electrolytic cell comgrising spaced anodes formed of graphite, aa cathode in position for cooperatin' with said anodes, current being,dehvered, bring the operation of the cell, to all parts of the cathode,the anodes covering each other transversely of the cathode, andpresenting thereto a substantially unbroken surface, spaced subistantially uniformly from the cathode.

In testimony whereof I hereunto aflix my signature. OTTMAR CONRADTY.

aphragm and

